Current Topics in Cellular Regulation, Volume 13 emphasizes the basic mechanisms involved in the regulation of diverse cellular activities. This book discusses the enzymology of aminoacyl-tRNA protein transferases, analysis of mutant phenotypes, and protein kinase reaction with pyruvate kinase as substrate. The rapid hormonal regulation of pyruvate kinase in vivo, interconvertible enzyme cascades in metabolic regulation, monocyclic cascade systems, and metabolism of fructose in the liver are also elaborated. This publication likewise covers the influence of fructose on lipid metabolism, lactose operator-repressor interaction, and regulation of nitrogenase synthesis. Other topics include the involvement of isozymes in metabolic regulation and molecular approach to the complement system. This volume is a good reference for biologists and researchers conducting work on the advances in the general area of cellular regulation.